Week 9

.docx

School

Rutgers University *

*We aren’t endorsed by this school

Course

208

Subject

Anatomy

Date

Feb 20, 2024

Type

docx

Pages

3

Uploaded by MegaWombat55

Shoulder 1. Describe the scapular plane 1. It has a very important function due to the fact that muscles are in better alignment and the capsule is not twisted. 2. What are the four joints of the shoulder 1. They are the glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic. 3. Describe the characteristics of the SC joint 1. The SC joint links the UE with thorax, it is small articulation with the 1 st rib, the Synovial joint with fibrocartilaginous disc that divides the joint into two compartments. Disc prevents medial and inferior displacement. 50 degrees of axial rotation 35 degrees of superior-inferior and anterior- posterior translation. 4. Describe the importance of the clavicle 1. The clavicle connects the arm to the thorax, S-shaped joint, it protects the brachial plexus and vasculature. The ration of 4 degrees of clavicular elevation with every 10 degrees of arm elevation with majority of elevation at SC joints. 5. Describe the importance of the labrum 1. The labrum is a fibrocartilage ring that deepens the socket by 50%. The superior portion is consistent with the long head of biceps at supraglenoid tubercle biceps at supraglenoid tubercle. With intact labrum, the shoulder can resist tangential forces of 60% of the compressive load; resection of the labrum can only resist 20% of the compressive load. SLAP lesion can occur from traction or compression; causes include overhead activities, sudden pull on the arm or FOOSH, causing severe pain and instability pain and instability. Treatment of SLAP lesion 6. Describe what occurs with the shoulder joint capsule with various motions 1. Joint capsule: attaches onto and around the labrum, it reaches the anatomical neck of the humerus, attaches to the base of the coracoid enveloping the long head of the biceps. 2. Adduction: superior capsule tightens. 3. Abduction: inferior capsule tightens. 4. IR: tightening posteriorly 5. ER: tightening anteriorly 6. Posterior capsule: it restrains anterior translation, primary posterior stabilizer 7. Describe the main job of the superior GHL 1. It originates from the anterior superior labrum and inserts to the lesser tuberosity. The main restraint is inferior translation with arm in resting or adducted position. 8. Describe the function of the inferior GHL 1. It originates from an inferior aspect of the labrum and inserts on anatomical neck of humerus. It has three components: anterior band, posterior component, axillary pouch. The primary anterior stabilizer of shoulder with arm in 90 degrees of abduction (IR the anterior band restrains; ER the posterior band retrains). Resists inferior translation with arm abducted. 9. Describe the scapulohumeral rhythm
1. The ratio of the glenohumeral movement to the scapulothoracic movement during arm elevation. This is most often calculated by dividing the total amount of shoulder elevation (humero thoracic) by the scapular upward rotation (scapulothoracic). 10. What are the four rotator cuff muscles and what do they do 1. Supraspinatus: forms force couple with deltoid for abduction 2. Infraspinatus and teres minor: ER of humerus 3. Subscapularis: IR, anterior stabilizer of humerus with arm abducted at 45 degrees 4. Teres minor ADD and IR 11. Describe the convex concave rule with the shoulder with flexion, abduction, and external rotation 1. External rotation of the glenohumeral joint, the convex part (head of the humerus) will glide anteriorly, while it will roll posteriorly on the concave part (in this case, the glenoid) – similar to the reasoning we have for the apprehension test. 12. Describe what occurs with shoulder impingement 1. The top outer edge of your shoulder blade, called the acromion, rubs against or pinches your rotator cuff beneath it, causing pain and irritation. Elbow 1. Describe the articulations of the elbow 1. humero-ulnar: flexion and extension 2. humero-radial: flexion/extension & pronation and supination 2. Describe the trochlea and the capitellum 1. Trochlea is between the two columns, forming an arc of 330 degrees covered by hyaline cartilage. 2. Capitellum covered by hyaline cartilage as well forms an arc of 180 degrees. 3. Describe the functional range of motion of the elbow 1. Functional range of motion for flexion and extension: 30-130 degrees. 2. Functional range of motion for pronation and supination: 50 degrees to 50 degrees. 3. Flexion contractures greater than 30 degrees are related to loss of function. 4. Axis of rotation of flex/ext has a changing axis and is more complex than uniaxial hinge; however articulation between proximal ulna and distal humerus is generally uniaxial except at extremes of flex/extension. 4. What occurs with the radial head with flexion and extension of the elbow 1. When the elbow is flexed the radial head approximates the capitellum.  2. when the elbow extends the radial head distracts from the capitellum 5. Describe what occurs with the MCL and LCL bundles during elbow flexion and extension 1. With extension, the elbow articulation is stable from varus stresses, followed by the anterior capsule and the LCL; limited by anterior capsule and anterior bundle of MCL. 2. Anterior bundle tightens with extension and posterior bundle tightens with flexion. 6. What muscles are involved with elbow flexion
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help